These polyfluorinated alcohols and esters are valuable intermediates for the production of surface-active agents and hydrophobic and oleophobic substances. In particular, they may easily be converted into acrylic or methacrylic esters. The polymerization of these esters optionally with other monomers, gives hydrophobic and oleophobic finishing agents for textile materials, leather, paper or other substrates. Alcohol and ester mixtures may also be converted entirely into alcohols.
Several processes for the preparation of these polyfluorinated alcohols and esters are known. The process described in French Pat. No. 1,380,579, which reacts an iodide R.sub.F CH.sub.2 CH.sub.2 I with fuming sulphuric acid and then hydrolyzes the sulphate formed. It has the disadvantage of producing large quantities of sulphuric diesters. These diesters are difficult to hydrolyze. The reference is hereby incorporated by reference.
According to the process described in U.S. Pat. No. 3,239,557, it is possible to obtain the esters R.sub.F CH.sub.2 CH.sub.2 OCOR by reacting an iodide R.sub.F CH.sub.2 CH.sub.2 I with a salt of a carboxylic acid RCOOH. However, the yields are not very high because variable quantities of the olefin R.sub.F CH.dbd.CH.sub.2 are formed. The patent is hereby incorporated by reference.
The alcohols R.sub.F CH.sub.2 CH.sub.2 OH may also be obtained according to the process of French Pat. No. 2,096,179, hereby incorporated by reference, which relates to preparing the nitrates R.sub.F CH.sub.2 CH.sub.2 ONO.sub.2 by reacting the iodides R.sub.F CH.sub.2 CH.sub.2 I with nitric acid and to hydrogenating these nitrates into alcohol. However, this process had the disadvantage of requiring two reaction stages, the latter of which must be carried out under a high hydrogen pressure.
French Pat. No. 2,180,113, hereby incorporated by reference, describes a process for the production of mixtures of alcohols R.sub.F CH.sub.2 CH.sub.2 OH and formates R.sub.F CH.sub.2 CH.sub.2 OCOH by reacting the iodides R.sub.F CH.sub.2 CH.sub.2 I with dimethylformamide at high temperature in the presence of a small quantity of water. This process has the disadvantage of requiring very harsh reaction conditions and of producing the olefin R.sub.F CH.dbd.CH.sub.2 as a by-product. This reduces the yield accordingly. Additionally, a good selectivity for alcohol and formate can only be obtained by using very large quantities of dimethylformamide.
More recently, the preparation of these polyfluorinated alcohols and esters by reacting the iodide R.sub.F CH.sub.2 CH.sub.2 I with a peroxacid RCO.sub.3 H which has previously been formed by adding hydrogen peroxide to a carboxylic acid RCO.sub.2 H in the presence or otherwise of a small quantity of sulphiric acid has been proposed in European Pat. No. 24,224 and West German Pat. No. 3,035,641. However, under the operating conditions described, this process leads to the production of an olefin by-product R.sub.F CH.dbd.CH.sub.2 in a significant quantity and/or to a low conversion rate for the iodide R.sub.F CH.sub.2 CH.sub.2 I. The patents are hereby incorporated by reference.
A process which enables these disadvantages to be overcome, that is, the production of the olefin by-product R.sub.F CH.dbd.CH.sub.2 is prevented and an excellent conversion rate is obtained, has now been discovered.